1 files changed, 133 insertions, 0 deletions
diff --git a/notes/changes.md b/notes/changes.md
new file mode 100644
index 0000000..66389d9
--- /dev/null
+++ b/notes/changes.md
@@ -0,0 +1,133 @@
+# Changes
+
+## May 27, 2026
+
+### Chunk-Based Message Refactor (`ca6ee91`)
+
+Replaced the flat `content: string` + `thinking: string` message model with an ordered
+`chunks: Chunk[]` union that preserves actual temporal ordering of events from the model.
+
+**New chunk types:**
+
+| Type | Body | Emitted on |
+|------|------|-----------|
+| `text` | `text: string` | `text-delta` events, coalesced |
+| `thinking` | `text: string` | `reasoning-delta` events, coalesced |
+| `tool-batch` | `calls: Array<{id, name, arguments, result?, isError?, shellOutput?}>` | `tool-call` events, batched |
+| `error` | `message: string, statusCode?: number` | Error events |
+| `system` | `text: string, kind` | System notices (model-changed, config-reload, cancelled, rate-limit) |
+
+**Key design decisions:**
+- System events during active turn append inline to the assistant message's chunks
+- System events outside turns create/append `role: "system"` messages
+- `toCoreMessages` strips `error`/`system` chunks and `role: "system"` messages
+- `MessageRole` changed from `user | assistant | tool` → `user | assistant | system`
+- Tool calls/results embedded in `tool-batch` chunks, no separate `role: "tool"` messages
+
+**Files changed:**
+- `packages/core/src/types/index.ts` — `Chunk` union, `MessageRole` update
+- `packages/frontend/src/lib/types.ts` — mirrored types
+- `packages/core/src/chunks/append.ts` — `appendEventToChunks()` state machine + `applySystemEvent()` router
+- `packages/core/tests/chunks/append.test.ts` — 35 unit tests
+- `packages/core/src/db/index.ts` — removed `thinking` column from messages schema
+- `packages/core/src/db/messages.ts` — updated `appendMessage`/`getMessagesForTab`
+- `packages/core/src/agent/agent.ts` — single `chunks[]` accumulator, updated `toCoreMessages`
+- `packages/api/src/agent-manager.ts` — progressive persistence, system event routing
+- `packages/frontend/src/lib/tabs.svelte.ts` — unified `applyChunkEvent`, `openAgentTab` reads chunks
+- `packages/frontend/src/lib/components/ChatMessage.svelte` — per-type chunk renderers
+- `packages/frontend/src/lib/components/ToolCallDisplay.svelte` — prop updates
+
+**Database:** Messages and tabs tables dropped; settings, keys, credentials preserved.
+Backup at `~/.local/share/dispatch/dispatch.db.bak-20260527-181334`.
+
+---
+
+### Frontend Fixes
+
+#### Wire-format drift (`5261879`)
+
+`openAgentTab` expected `contentJson: string` on the wire but the API now returns
+`chunks: Chunk[]`. Fixed to read `m.chunks` directly with `Array.isArray` fallback.
+
+Also added diagnostic debug info to `copyConversation`: store state block
+(connection status, agentStatus, message counts) and per-message chunk summaries.
+
+#### structuredClone → $state.snapshot (`faeb8fe`)
+
+Svelte 5 `$state` proxies throw `DataCloneError` on native `structuredClone()`.
+Fixed by switching to `$state.snapshot()` in `applyChunkEvent` and `routeSystemEvent`.
+This was the root cause of `chunks=0` in production — every content event after
+placeholder creation silently failed.
+
+#### WS error swallowing (`faeb8fe`)
+
+`ws.svelte.ts` wrapped all callbacks in a single `try{} catch{}` that swallowed
+errors. Split into per-callback try/catch with `console.error`. Future bugs of
+this class are now diagnosable from the browser console.
+
+#### statuses reconnect handler (`faeb8fe`)
+
+Added `statuses` variant to `AgentEvent` union. On WS reconnect, handler syncs
+`agentStatus` for all tabs, detects desync (frontend thinks running, backend says
+idle/error), calls `reloadTabMessagesFromApi` to pull persisted chunks, and clears
+`currentAssistantId` and streaming flags.
+
+---
+
+### Model Routing Fix (`9ac04b9`)
+
+When a user selected a model (e.g., Gemini via configured key) but the corresponding
+API key environment variable was not set, `getOrCreateAgentForTab` in `packages/api/src/agent-manager.ts:610`
+set `useOverride = true` without updating `model` or `baseURL` from their defaults.
+The request silently went to `https://opencode.ai/zen/go/v1` with `model: "deepseek-v4-flash"`
+and no API key — OpenCode Go routed this to Claude, causing every model selection
+to respond with "I'm Claude, made by Anthropic."
+
+Fixed by setting `baseURL = key.base_url` and `model = effectiveModelId` in the
+missing-key branch so requests target the correct endpoint and produce a diagnosable
+auth error instead of a silent model-swap.
+
+---
+
+### Test Infrastructure Rewrite (`1e3f67e`)
+
+Replaced the POJO (plain-old-JavaScript-object) test harness in `packages/frontend/tests/chat-store.test.ts`
+with real `$state`-backed store instances via an exported `createTabStore()` factory
+and `handleEvent()` method.
+
+**What this catches that the old harness couldn't:**
+- Logic bugs in the actual `handleEvent` / `applyChunkEvent` / `routeSystemEvent` code
+- Drift between harness and production (now the same code)
+- Reactivity contract issues with real `$state` proxies
+
+**Known limitation:** The `structuredClone(svelteProxy)` bug cannot be reproduced in
+these tests because Bun's `structuredClone` (used by vitest) is more permissive than
+browser `structuredClone`. Catching that class of bug requires a browser-runtime test
+layer (Playwright, vitest browser mode).
+
+**Mocks:** `wsClient`, `config`, and `fetch` are mocked so module-load side effects
+(WebSocket connection, localStorage access, HTTP calls) don't interfere.
+
+**Files:**
+- `packages/frontend/src/lib/tabs.svelte.ts` — exported `createTabStore`, added `handleEvent`
+- `packages/frontend/tests/chat-store.test.ts` — 32 tests through the real reactive store
+
+---
+
+### Earlier: Read-System Fixes
+
+#### Path resolution (`da57842`)
+
+`read-file.ts`, `read-file-slice.ts`, `write-file.ts`, and `list-files.ts` used
+`resolve(join(workingDirectory, path))` which mangled absolute paths (e.g.,
+spill paths like `/tmp/dispatch/tool-results/...`). `join()` concatenates rather
+than short-circuiting on absolute segments.
+
+Fixed to use a shared `canonicalize()` helper in `packages/core/src/tools/path-utils.ts`
+that resolves via `realpath` and walks up to the nearest existing ancestor when the
+leaf doesn't exist (handles `write_file` creating new files through symlinked parent dirs).
+
+#### DEFAULT_LIMIT alignment
+
+Changed `DEFAULT_LIMIT` from 2000 → `MAX_LINES` (500) in `read-file.ts` so default
+reads don't always trigger truncator spills.